Codemasters posted this little tidbit on their website:

Codemasters Online and Turbine Inc are proud to unveil a new movie for the upcoming The Lord of the Rings Online™: Mines of Moria™ expansion pack due out later this year! This is your chance to get a first look at the Flaming Deeps, a brand new area within the dark depths in this breathtaking fly-through movie available for download from our downloads section.

You can find the video (in a zip file) right here!